Recently, wind turbines have received increased attention as environmentally safe and relatively inexpensive alternative energy sources. With this growing interest, considerable efforts have been made to develop wind turbines that are reliable and efficient.
Generally, a wind turbine includes a rotor having multiple blades. The rotor is mounted to a housing or nacelle, which is positioned on top of a truss or tubular tower. Utility grade wind turbines (i.e., wind turbines designed to provide electrical power to a utility grid) can have large rotors (e.g., 30 or more meters in length). In addition, the wind turbines are typically mounted on towers that are at least 60 meters in height. Blades on these rotors transform wind energy into a rotational torque or force that drives one or more generators that may be rotationally coupled to the rotor through a gearbox. The gearbox steps up the inherently low rotational speed of the turbine rotor for the generator to efficiently convert mechanical energy to electrical energy, which is fed into a utility grid. In order to provide the efficient conversion of mechanical energy to electrical energy, the wind turbine utilizes a variety of wind turbine components, such as shafts, gearing components, pitch drives, generator components and other components within the wind turbine. Such gears are subject to wear or damage, requiring servicing or repair.
Components in the wind turbine typically have to be installed, serviced or replaced using mobile land, or ocean-based cranes and/or manually carrying components to remove and/or replace components. Further, wind turbines may be installed on uneven terrain, in the ocean, and/or on very high towers (e.g., towers that are at least 60 meters in height) that are not easily accessible to mobile land-based or ocean-based cranes. In addition, operation of these large cranes is expensive and can require long lead times
Therefore, what is needed is an inexpensive method for servicing or repairing gear assemblies in wind turbines that is portable, lightweight and/or is capable of operation on-site and up-tower.